Pump



June 29, 1954 BRENNAN 2,682,226

' PUMP Filed Nov. 25, 1949 2 Sheets-Sheet 1 IN V EN TOR. J 0557i! .5. BEEN/VAN A TTOJEMEXS.

June 29, 1954 J N N 2,682,226

PUMP

Filed Nov. 25, 1949 2 Sheets-Sheet 2 IN V EN TOR.

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Patented June 29, 1 954 UNITED STATES PATENT OFFICE 9 Claims.

The present invention relates generally as indicated to a pump and more particularly to an automatic, high-pressure, variable capacity pump.

One primary object of this invention is to provide a variable capacity pump which is of simple, fool-proof construction and which has a high mechanical and volumetric efficiency.

Another object of this invention is to provide a reciprocating piston pump in which a plurality of double-ended pistons are actuated through the intermediary of a tilted ring engaged with each piston, preferably in rolling engagement in the manner of gear teeth to achieve high efficiency.

Still another object is the provision of novel means for adjusting said tilted ring to automatically vary the capacity or displacement of the pump.

Other objects and advantages will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following de scription and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

Fig. 1 is a top plan view of a preferred embodiment of this invention;

Fig. 2 is a cross-sectional view taken approximately along the line 2-2, Fig. 1;

Figs. 3 and 4 are transverse cross-sectional views taken respectively along the lines 3-3 and 4-4 of Fig. 2;

Fig. 5 is a plan view of one form of valve body employed in the present pump construction;

Fig. 6 is a cross-sectional view of said valve body taken substantially along the line 6-6, Fig. 5;

Fig. '7 is a fragmentary cross-sectional view of a modification employing a screw adjusted capacity-varying mechanism for the pump; and

Fig. 8 is a fragmentary cross-sectional view of a modification in the connection between a tilted ring and pistons actuated thereby.

Referring now to the drawings and first to the form of the invention illustrated in Figs. 1 through 6, there is provided a pump casing which comprises an intermediate tubular part I formed with one or more internal grooves 2 (herein six) milled or broached axially therethrough and with feet 3 for mounting the pump on a suitable support (not shown) At the ends of said intermediate part I are opposed cylinder blocks 4, preferably identical as shown but facing in opposite directions, and each formed with cylinder bores 5 axially therethrough in alignment with the grooves 2 in said intermediate part. Fitted into each of the cylinder bores 5 in said cylinder blocks i are liners or bushings 6 of bearing material. The outer face of each cylinder block 4 is formed with radially inwardly extending grooves or recesses l intersected by the respective bores 5.

Adjacent one of the cylinder blocks i is a head 8 which is formed with a pair of annular chambers 9 and I0 and a pair of ports H and i2 respectively leading to such chambers. Said head is further formed with two series of openings l4 and I5 leading from the respective chambers 9 and I0 into circular recesses I6 formed on the inner face of said head, such circular recesses being opposed to the radially inwardly extending recesses 1 formed in the adjacent cylinder block 4.

Fitted into each circular recess i6 is a valving assembly which comprises a circular disk or valve body I! non-rotatably fitted into the recess as by a dowel l8 thereon extending into a suitable opening in the bottom wall of the circular recess, said disk I! being formed with openings l9 and 2c therethrough respectively registering with the openings I4 and I5 in said head 8 and with oblong recesses 2| on opposite sides extending generally tangentially. In each of such oblong recesses 2! is a thin valve plate 23 which functions as a check valve to open and close communication through said disk IT in response to pressure or suction acting on opposite sides thereof and thereby controls the flow of fluid from and into the chambers 9 and [0 into and. from the respective expansible chamber which is defined by the cylinder bore 5 and the piston' reciprocable therein.

Said intermediate part I, cylinder block 4, and head 8 are secured together as by the studs 24 and nuts 25, as shown.

The head 26 at the other end of the pump casing adjacent the other cylinder block 4 is similar to the head 8 and insofar as said heads 8 and 26 are the same, the same reference numerals have been used to indicate the various chambers, parts, openings, valving assemblies, etc. associated therewith.

Adjacent said head 26 is an actuator housing- 3 the mechanism for effecting variation of the capacity of the pump. As shown, the intermediate casing part I, cylinder block 4, head 26, and actuator housing 21 are secured together by any suitable means such as the studs 28 and nuts 29 shown.

Reciprocable in the cylinder bores of said cylinder blocks 4 are the opposite ends of pistons 30 each of which has an intermediate section 3! of rectangular cross-section in sliding engagement in the grooves 2 formed in the intermediate casing part I. Said intermediate section of each piston 39 is also formed with an inwardly opening recess 32, preferably similar in general form to the space between the teeth of a gear rack.

J ournalled within the pump casing as'by antifriction bearings 34 carried in the opposed cylinder blocks and extending through the bushing 35 in head 8 is a drive shaft 36 having a splined end portion 31 through which the shaft'may be driven.

Carried by saiddriveshaft 35 for rotation therewith and for tilting movement thereon is a ring assembly 38 comprising an inner ring 39, an anti-friction bearing 40,'and an outer ring 4i, said inner ring 39 having'a'sp'ecially formed bore 42 therein permitting tilting thereof with respect to the drive shaft about theaxis of a pin 43 disposed transversely through said drive shaft with the opposite ends thereof extending into said inner ring, and said outer ring-4| being formed with a seriesof radial projections 45 of general form similar to spur gear teeth which tiltably fit into the inwardly directed recesses 32 formed in said pistons 30. Thus said'projections have a high efficien'cy'rolling engagement with recesses 32 comparablewith 'the'en'gagement of the teeth of a spur gear andrack. Said inner ring 39 is further'formed with a lateral ear portion 46 radially spaced fromthe' axis of said pin 43.

The mechanism for tilting'the above-described ring assembly '38 comprises a ring-like tilting member 41 non-rotatably' but axially slidably carried by said shaft '36 'andc'onnected to said inner ring 39 'as by means of a link 48 having its opposite ends pivotally' connected to the outer portion of said member and to the'ear portion 46 of said'inner As now apparent, axial movement of said member i? will; throughthe'linl "48, effect desired tilting of the inner ring 39 and thus of the entire ring assembly 38 about the axis of pin 43. The axial sliding and'n'on-rotary connection of said member 41 to the drive shaft is effected as by a transversely disposed pin 49 having its ends fitted into said member and extending through an axially-elongated slot 50'formed in the drive shaft.

The operation 'of the structure thus far described is as follows.

Assuming that the ring assembly' 38 is in a tilted position, as shown, the rotationof the drive shaft 35 wi1l-effect, through the pin- 43, rotation of the ring assembly-tbout the axis 51' to thereby effect reciprocationof each of thepistons 39 to draw fluid into one cylinder'bore 5 at one end, through port ll, chamber 9," opening [4, and opening I9 and to discharg'fluid' from the other cylinder bore 5 at the opposite end through the opening 29, opening 15, and discharge chamber I0 and port 12. 'As apparentfthe check valves are operative to alternatelyopen-and close communication between cylinder bore 5 and chambers 9 and I0.

In the particular pump shown employing six double-ended pistons 39, fluid will be drawn into and discharged from twelve expanding chambers and twelve contracting chambers during each revolution of the drive shaft 38 and because of the uniform spacing of the pistons 33, the delivery at any instant is .a constantwhereby to eliminate pulsation. Of course, the capacity or displacement of the pump will vary in accord- :ance with the tilt of the ring assembly 38 and will be zero when the ring assembly is perpendicular to the drive shaft.

Referring now to the feature of automatic variation in the capacity of the pump, the end of the drive shaft 36 which extends through the head 26 is hollow and has slidably fitted thereinto a rod 52 and through which rod the pin 49 extends whereby reciprocation of said rod will correspondingly reciprocate the above-described member i t. Adjacent the outer end'of said head 26 and reciprocable within the actuator housing 21 is a piston 53 and a ball 54 in the hollow end of the drive shaft is engaged between the end of said rod 52 and said piston 53.

Formed in the actuator housing 2'! is a vfluid chamber 55 in which a spring actuated plunger El is reciprocable to maintain a uniform pressure on the fluid in such chamber and thereby through the body of fluid acting on the piston 53 tend to urge the latter toward the right as viewed in'Fig. 2 and through the ball 54, rod 52, pin 49, member 41, and link 48 tend to tilt the ring assembly 38 to a position to increase the capacity of the pump in opposition to the resistance to such tilting afforded by the fluid under pressure discharged from the pump acting on the ends-of the pistons 30. The spring 58 for actuating the plunger bears against said plunger 51 and against a closure cap 59 threaded into the actuator housing. Said housing 2'! is formed with a pair of ports 60 and El providing an inlet and discharge for fluid under pressure into and from such chamber 56.

As previously indicated, one function of the spring actuated plunger 51 is to smooth-out any fluctuations in the fluid under pressure in the chamber whereby to maintain a more constant pressure acting upon the piston 53.

As apparent, a decrease of the fluid under pressure in the chamber 55 will permit the pressure acting on the ends of the pistons '30 to shift the ring assembly 33120 or toward anon-tilted position, thereby reducing the" displacement ,of the pump to a desired value or to zero.

The ports 60 and GI in the actuator housing 27' may optionally be connected into the discharge lines of the pump or to a separate source of" fluid under pressure whereby in such latter instance remote control of the variation in the capacity of the pump may be conveniently :effected.

A modification of the present invention as illustrated in Fig. 8 comprises pistons each'of which is formed with a peripheral groove" 56 therearound in its intermediate section (31. 'L.In this case the outerring '69 ofthe tiltable ring assembly may, if desired, be formed with a continuous ring portion 59 tiltably fitting within such peripheral groove. Moreover, the. intermediate section 6'! may be of circular cross-section, in which case the grooves inthe intermediate casing part II are not required forsthe purpose of non-rotatably supporting the-pistons as in Fig. 2 but may be provided for the purpose of preventing bending of the pistons and thereby reducing stresses at the ends of the pistons.

A still further modification of the present invention as illustrated in Fig. 7 comprises a sleeve 15 corresponding with the rod 52 in Fig. 2, said sleeve containing a spring 16 and spring guide '18 therein, a screw 19 adjustable in the end plate 11 on head 80 which is of construction similar to the head 26 previously described, and a ball 8| interposed between the end of said screw 19 and said guide 18. As apparent, adjustment of the screw 19 will effect corresponding adjustment of the tilt of the ring assembly through axial movement of the pin 82 which extends transversely through said sleeve and the axially elongated slot 83 in the drive shaft 84 and is connected to the member 41. Here again, as in the form of the invention illustrated in Figs. 1-6, the tiltable ring assembly is yieldably held by spring 16 in a desired adjusted tilted position in accordance with the setting of the screw 19.

The above-described embodiments of this invention are, of course, to be regarded as merely typical and, as obvious, the structure illustrated in Figs. 1-6 may incorporate either or both of the modifications illustrated in Figs. 7 and 8.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A pump comprising a hollow casing formed with fluid inlet and discharge passages at op- Y posite ends and at least two coaxial cylinder bores respectively communicating with such passages, a piston having its opposite ends reciprocable within such cylinder bores, check valves interposed between such cylinder bores and adjacent passages operative to open communication between an intake passage and cylinder bore during movement of said piston in one direction and to open communication between a cylinder bore and discharge passage during movement of said piston in an opposite direction, a drive shaft journalled in said casing, and a ring carried by said shaft for rotation therewith and engaged with an intermediate section of said piston, said casing being formed with a groove parallel to such bores in which groove the intermediate section of said piston is slidable.

2. A pump comprising a hollow casing formed with fluid inlet and discharge passages at opposite ends and at least two coaxial cylinder bores respectively communicating with such passages, a piston having its opposite ends reciprocable within such cylinder bores, check valves interposed between such cylinder bores and adjacent passages operative to open communication between an intake passage and cylinder bore during movement of said piston in one direction and to open communication between a cylinder bore and discharge passage during movement of said piston in an opposite direction, a drive shaft journalled in said casing, and a ring carried by said shaft for rotation therewith and engaged with an intermediate section of said piston, said casing being formed with a groove parallel to such bores and of cross-section complementary with that of the intermediate section of said piston, the intermediate section of said piston being of non-circular cross-section whereby to be nonrotatable in such groove, said piston being formed with a recess, and said ring being formed with a projection extending into and tiltable within such recess.

3. A pump comprising a casing part of tubular form provided with a plurality of uniformly spaced, axially extending grooves in its inner surface, a cylinder block at each end of said casing part formed with cylinder bores axially therethrough in alignment with such grooves, a head adjacent each cylinder block formed with fluid inlet and discharge passages leading to the cylinder bores in the adjacent cylinder block, a plurality of pistons slide-guided in such grooves and having their opposite ends reciprocable within such cylinder bores, a drive shaft rotatably supported within said casing part and cylinder blocks and extending exteriorly through one of said heads, a tilted ring non-rotatable on said shaft and engaged with each of said pistons whereby to effect reciprocation of said pistons during rotation of said shaft and ring, and valve means between said heads and blocks for alternately opening and closing communication between such cylinder bores and such inlet and discharge passages during reciprocation of said pistons.

4. A pump comprising a casing part of tubular form provided with a plurality of uniformly spaced, axially extending grooves in its inner surface, a cylinder block at each end of said casing part formed with cylinder bores axially therethrough in alignment with such grooves, a head adjacent each cylinder block formed with fluid inlet and discharge passages leading to the cylinder bores in the adjacent cylinder block, a plurality of pistons slide-guided in such grooves and having their opposite ends reciprocable within such cylinder bores, a drive shaft rotatably supported within said casing part and cylinder blocks and extending exteriorly through one of said heads, a tilted ring non-rotatable on said shaft and engaged with each of said pistons whereby to effect reciprocation of said pistons during rotation of said shaft and ring, and valve means between said heads and blocks for alternately opening and closing communication between such cylinder bores and such inlet and discharge passages during reciprocation of said pistons, a pin transversely through said shaft and ring supporting the latter for tilting movement with respect to said shaft, mechanism for tilting said ring slidable axially on and non-rotatable with respect to said shaft, said mechanism being connected to said ring at a point radially spaced from the axis of said pin whereby to effect adjustment of the tilt of said ring upon axial movement of said mechanism, and means for axially moving said mechanism on said shaft.

5. The structure according to claim 4 further characterized in that said last-named means comprises an actuator housing adjacent one of said heads formed with a chamber for fluid, a piston reciprocable in said housing and engageable with said tilting mechanism, and a spring actuated plunger in such chamber adapted to exert pressure on fluid in such chamber to actuate said piston.

6. A drive shaft assembly for pumps comprising a shaft, a ring non-rotatably but 'tiltably mounted on said shaft for tilting about an axis transverse to the longitudinal axis of said shaft, a first member for tilting said ring non-rotatably connected to said ring and axially slidable on .said shaft operative to tilt said ring responsive to relative axial movement of said member and 7. shaft, said shaft being hollow at one end with a slot transversely through the wall thereof, and a second member axially reciprocable within said shaft and connected through such slot to said first member to axially shift the latter.

'7. A pump comprising a hollow casing formed with fluid inlet and discharge passages at opposite ends and at least two coaxial cylinder bores respectively communicating with such passages, a piston having its opposite ends reciprocable within such cylinder bores, check valves interposed between such cylinder bores and adjacent passages operative to open communication between an intake passage and cylinder bore during movement of said piston in one direction and to open communication between a cylind r bore and discharge passage during movement of said piston in an opposite direction, a drive shaft journalled in said casing, and a ring carried by said shaft for rotation therewith and engaged with an intermediate section of said piston, said casing being formed with a groove of cross-sec tion complementary with that of the intermediate section of said piston, in which the intermediate section of said piston is slidably fitted, said piston being formed with a recess, and said ring being formed with a projection extending into and tiltable within such recess, such projection being in the general form of a gear tooth having a rolling action in such recess.

8. A pump comprising a hollow casing formed with fluid inlet and discharge passages at opposite ends and at least two coaxial cylinder bores respectively communicatin with such passages, a piston having its opposite ends reciprocable within such cylinder bores, check valves interposed between such cylinder bores and adjaeent passages operative to open communication between an intake passage cylinder bore during movement of said piston in one direction and to open communication between a cylinder bore and discharge passage during movement of said piston in an opposite direction, a drive shaft journalled in said casing, and a ring carried by said shaft for rotation therewith and engaged with an intermediate section of said piston, said casing being formed with a groove of cross-section complementary with that of the intermediate section of said piston, in which the intermediate section of said piston is slidably fitted, said piston being formed with a recess, and said ring comprising an inner member carried by said shaft for rotation therewith and an outer member rotatable on said inner member and being formed with a projection extending into and tiltable within such recess, such projection being in the general form of a gear tooth having a rolling action in such recess.

9. A pump comprising a casing formed with fluid inlet and discharge passages at opposite ends and at least two coaxial cylinder bores respectively communicating with such passages, .a piston having its opposite ends reciprocable within such cylinder bores, a drive shaft rotatably supported in said casing, a member carried by said shaft for rotation therewith and for tilting movement thereon, mechanism for adjustably tilting,

said member on said shaft, said piston being formed with a cut-away portion, said member being formed with a projection extending into and tiltable within such cut-away portion, and such projection being in the general form of a gear tooth having a rolling action in such cutaway portion, and valve means within said casing to alternately open andclose communication between such cylinder bores and passages during rotation of said shaft and subsequent reciprocation of said piston in such cylinder bores.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,014,860 Mitchell Sept. 1'7, 1935 2,169,456 Wahlmark Aug. 15, 1939 2,215,700 Heideman Sept. 2 1, 1940 2,329,912 Kent et a1 Sept. 21, 1943 2,373,723 Wahlmark Apr.'17, 1945 2,392,543 Mercier Jan. 8, 1946 2,392,980 Fawkes Jan. 15, 1946 FOREIGN PATENTS Number Country Date 771,419 France 1934 

